A self-checking processor is a processing system that has redundant hardware used to detect faults in the system. A common self-checking processor (SCP) has two similar processors having two processing lanes. Faults are typically detected when the outputs of the two processing lanes differ. However, the SCP is susceptible to a class of faults existing in both processing lanes which are referred to as common-mode or generic faults. Both software and hardware design faults as well as common mode hardware manufacturing faults are common-mode faults that go undetected due to the complexity of the processor hardware, such as a complex high performance processor. This type of fault affects both processors of the SCP similarly, thus both processors output identical but wrong data when a fault is present. Because the outputs are identical, the SCP cannot detect these faults without an additional dissimilar processor to compare to the similar processors. This requires at least one of the similar processors to also execute a check of the dissimilar processor's function as an independent verification of the dissimilar processor's execution, thus increasing the performance demanded on at least one of the similar processors and the overall power required by the SCP.